Surgical stapling device with firing lockout mechanism

ABSTRACT

A surgical stapling device includes a tool assembly and a drive assembly for actuating the tool assembly. The tool assembly includes a cartridge assembly having a staple cartridge and an anvil assembly that supports a lockout mechanism. The staple cartridge includes a cartridge body and an actuation sled and knife assembly that includes an actuation sled and a knife. The actuation sled and knife assembly is movable in relation to the cartridge body to eject staples from the cartridge body and to cut tissue. The anvil assembly supports a lockout mechanism that includes a lockout member that is movable between a locked position and an unlocked position. The drive assembly is movable from a retracted position to an advanced position to move the actuation sled and knife assembly from its retracted position to its advanced position. In the locked position, the lockout member obstructs movement of the drive assembly from its retracted position towards its advanced position.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.17/488,511, filed Sep. 29, 2021, now U.S. Pat. No. 11,653,922, which isincorporated by reference herein in its entirety.

FIELD

The disclosure is directed to surgical stapling devices having staplecartridges and, more particularly, to surgical stapling devices withlockout mechanisms to prevent firing of the stapling device when a knifeis not present in the staple cartridge.

BACKGROUND

Surgical stapling devices for simultaneously stapling and cutting tissueare well known in the art and include a tool assembly and a driveassembly. The tool assembly includes an anvil assembly and a cartridgeassembly having a channel member and a staple cartridge that is receivedwithin the channel member. Typically, the staple cartridge includes acartridge body that supports staples, pushers, and an actuation sled.The actuation sled is movable through the cartridge body from aretracted position to an advanced position into sequential engagementwith the pushers to sequentially eject the staples from the cartridgebody.

In some stapling devices, a knife is supported on the actuation sled andis movable with the actuation sled through the cartridge body. The driveassembly is positioned proximally of the actuation sled and is movablein relation to the anvil and cartridge assemblies to advance theactuation sled and knife through the staple cartridge to move the toolassembly between open and clamped positions, to eject the staples fromthe cartridge body, and to cut tissue clamped between the anvil andcartridge assemblies. After the stapling device is fired, the actuationsled and knife remain in a distal portion of the staple cartridge.

When a stapling device is fired with a staple cartridge that does nothave an actuation sled and/or a knife present in a proximal portion ofthe staple cartridge, staples will not be ejected from the staplecartridge and tissue will not be cut. A continuing need exists for alock mechanism of simple construction that can prevent advancement of adrive assembly of a stapling device through the staple cartridge when asled and/or knife is not present in the proximal portion of the staplecartridge.

SUMMARY

This disclosure is directed to a stapling device having a tool assemblyincluding a cartridge assembly, an anvil assembly, and a drive assembly.The anvil assembly supports a lockout mechanism that preventsadvancement of the drive assembly when the cartridge assembly does nothave an actuation sled or knife present in a proximal portion of thecartridge assembly.

Aspects of this disclosure are directed to a surgical stapling devicethat includes an elongate body, a tool assembly, and a drive assembly.The elongate body has a proximal portion and a distal portion. The toolassembly is supported on the distal portion of the elongate body andincludes a cartridge assembly and an anvil assembly that are coupledtogether to facilitate movement of the tool assembly between open andclamped positions. The cartridge assembly includes a staple cartridgehaving a cartridge body, staples, pushers, and an actuation sled andknife assembly. The actuation sled and knife assembly includes anactuation sled and a knife supported on the actuation sled for movementbetween raised and lowered positions. The actuation sled and knifeassembly is movable within the cartridge body from a retracted positionto an advanced position to eject the staples from the cartridge body andto cut tissue clamped between the cartridge and anvil assemblies. Theanvil assembly includes a lockout mechanism that is linearly movablefrom a locked position to an unlocked position. The actuation sled andknife assembly is positioned to urge the lockout mechanism to itsunlocked position when the actuation sled and knife assembly is in itsretracted position. The drive assembly is positioned proximally of theactuation sled and knife assembly and is movable in relation to the toolassembly between a retracted position and an advanced position to movethe tool assembly between the open and clamped positions and to move theactuation sled and knife assembly from its retracted position to itsadvanced position. The lockout mechanism is positioned to preventmovement of the drive assembly from its retracted position to itsadvanced position when the lockout mechanism is in its locked position.

In aspects of the disclosure, the lockout mechanism includes a lockoutmember that is movable between the locked and unlocked positions.

In some aspects of the disclosure, the lockout mechanism includes abiasing member that is positioned to urge the lockout member to thelocked position.

In certain aspects of the disclosure, the anvil assembly includes ananvil plate that supports a housing that defines an opening, and thelockout member and the biasing member are positioned within the housing.

In aspects of the disclosure, the lockout member is movable through theopening in the housing between the locked and unlocked positions.

In some aspects of the disclosure, the anvil assembly includes an anvilplate that defines a central knife slot that defines a longitudinalaxis, and the lockout member extending across at least a portion of thecentral knife slot when the lockout member is in the locked position.

In certain aspects of the disclosure, the drive assembly includes aworking member that has an I-beam configuration and includes a firstbeam, a second beam, and a vertical strut that connects the first beamto the second beam.

In aspects of the disclosure, the vertical strut is positioned totranslate through the central knife slot of the anvil plate as the driveassembly moves between its retracted and advanced positions.

In some aspects of the disclosure, the lockout member has a distallyfacing cam surface that defines a plane that forms an acute angle withthe longitudinal axis of the central knife slot of the anvil plate.

In certain aspects of the disclosure, the distally facing cam surfaceengages the vertical strut of the drive assembly as the drive assemblyis moved from the advanced position to its retracted position to movethe lockout member from the locked position to the unlocked position.

In aspects of the disclosure, the lockout member includes a proximallyfacing stop surface that defines a plane that is substantiallyperpendicular to the longitudinal axis of the central knife slot of theanvil plate.

In some aspects of the disclosure, the knife of the actuation sled andknife assembly is positioned to engage the lockout member when theactuation sled and knife assembly is in a retracted position to retainthe lockout member in the unlocked position.

Other aspects of the disclosure are directed to a tool assembly thatincludes a cartridge assembly, an anvil assembly, and a lockoutmechanism. The cartridge assembly includes a staple cartridge having acartridge body, staples, pushers, and an actuation sled and knifeassembly. The actuation sled and knife assembly includes an actuationsled and a knife that is supported on the actuation sled for movementbetween raised and lowered positions. The actuation sled and knifeassembly is movable within the cartridge body from a retracted positionto an advanced position to eject the staples from the cartridge body andto cut tissue clamped between the cartridge and anvil assemblies. Theanvil assembly is coupled to the cartridge assembly to facilitatemovement of the tool assembly between open and clamped positions. Thelockout mechanism is supported on the anvil assembly and is linearlymovable from a locked position to an unlocked position. The actuationsled and knife assembly is positioned to urge the lockout mechanism toits unlocked position when the actuation sled and knife assembly is inits retracted position.

Still other aspects of the disclosure are directed to a tool assemblythat includes a cartridge assembly, an anvil assembly, and a lockoutmechanism. The cartridge assembly includes a staple cartridge having acartridge body, staples, pushers, and an actuation sled and knifeassembly. The actuation sled and knife assembly includes an actuationsled and a knife. The actuation sled and knife assembly is movablewithin the cartridge body from a retracted position to an advancedposition to eject the staples from the cartridge body and to cut tissueclamped between the cartridge and anvil assemblies. The anvil assemblyis coupled to the cartridge assembly to facilitate movement of the toolassembly between open and clamped positions. The lockout mechanism issupported on the anvil assembly and is linearly movable from a lockedposition to an unlocked position. The actuation sled and knife assemblyis positioned to urge the lockout mechanism to its unlocked positionwhen the actuation sled and knife assembly is in its retracted position.

Other features of the disclosure will be appreciated from the followingdescription.

BRIEF DESCRIPTION OF THE DRAWINGS

Various aspects of the disclosure are described herein below withreference to the drawings, wherein:

FIG. 1 is side perspective view of a stapling device according toaspects of the disclosure including a tool assembly in an open position;

FIG. 2 is a side perspective view of the tool assembly of the staplingdevice shown in FIG. 1 with a staple cartridge separated from a channelmember of a cartridge assembly of the tool assembly;

FIG. 3 is an enlarged view of the indicated area of detail shown in FIG.2 illustrating a proximal portion of the cartridge assembly;

FIG. 4 is a side perspective view of an actuation sled and knifeassembly of the staple cartridge shown in FIG. 2 ;

FIG. 5 is an exploded view of the staple cartridge of the cartridgeassembly shown in FIG. 2 ;

FIG. 5A is a side perspective, exploded view of the actuation sled andknife assembly of the staple cartridge shown in FIG. 5 ;

FIG. 6 is a side perspective view of an anvil assembly of the toolassembly shown in FIG. 2 ;

FIG. 7 is an enlarged view of the indicated area of detail shown in FIG.6 illustrating a lockout mechanism;

FIG. 8 is a side perspective view of a lockout member of the lockoutmechanism shown in FIG. 7 ;

FIG. 9 is a top perspective view of the lockout member of the lockoutmechanism shown in FIG. 7 ;

FIG. 10 is a top view of a proximal portion of the anvil assembly shownin FIG. 6 ;

FIG. 11 is an enlarged view of the indicated area of detail shown inFIG. 10 ;

FIG. 12 is a perspective view from a first side of a distal portion of adrive assembly of the stapling device shown in FIG. 1 ;

FIG. 13 is a perspective view from a second side of the distal portionof the drive assembly shown in FIG. 12 ;

FIG. 14 is an enlarged view of the indicated area of detail shown inFIG. 2 ;

FIG. 15 is a side perspective of the proximal portion of the toolassembly of the stapling device shown in FIG. 1 with the anvil assemblyand the cartridge assembly shown in phantom as a working member of thedrive assembly is advanced from a retracted position to a position tomove the tool assembly to the clamped position;

FIG. 16 is a schematic view illustrating the positions of the lockoutmechanism, the working member of the drive assembly, and knife of theactuation sled and knife assembly prior to engagement of the knife withthe lockout mechanism;

FIG. 17 is a side perspective view of the working member of the driveassembly and the actuation sled and knife assembly as the drive assemblylifts the knife of the actuation sled and knife assembly from a loweredposition to a raised position;

FIG. 18 is a schematic view illustrating the positions of the lockoutmechanism, the working member of the drive assembly, and knife of theactuation sled and knife assembly with the knife engaged with thelockout mechanism to move the lockout mechanism from a locked positionto an unlocked position;

FIG. 19 is a top view of a proximal portion of the anvil assembly andthe drive assembly as the drive assembly returns to its retractedposition after the stapling device has been fired with the lockoutmechanism retained in the unlocked position by the drive assembly; and

FIG. 20 is a top view of the proximal portion of the anvil assembly andthe distal portion of the drive assembly shown in phantom with the driveassembly in its retracted position and the lockout mechanism in thelocked position.

DETAILED DESCRIPTION

The disclosed surgical stapling device will now be described in detailwith reference to the drawings in which like reference numeralsdesignate identical or corresponding elements in each of the severalviews. However, it is to be understood that aspects of the disclosureare merely exemplary of the disclosure and may be embodied in variousforms. Well-known functions or constructions are not described in detailto avoid obscuring the disclosure in unnecessary detail. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the disclosure in virtually any appropriately detailed structure.

In this description, the term “proximal” is used generally to refer tothat portion of the device that is closer to a clinician during use ofthe stapling device in its customary manner, while the term “distal” isused generally to refer to that portion of the device that is fartherfrom the clinician during use of the stapling device in its customarymanner. In addition, the term “clinician” is used generally to refer tomedical personnel including doctors, nurses, and support personnel.Further, directional terms such as front, rear, upper, lower, top,bottom, and similar terms are used to assist in understanding thedescription and are not intended to limit the disclosure.

The disclosed surgical stapling device includes a tool assembly and adrive assembly for actuating the tool assembly. The tool assemblyincludes a cartridge assembly having a staple cartridge and an anvilassembly that supports a lockout mechanism. The staple cartridgeincludes a cartridge body and an actuation sled and knife assembly thatincludes an actuation sled and a knife. The actuation sled and knifeassembly is movable in relation to the cartridge body to eject staplesfrom the cartridge body and to cut tissue. The anvil assembly supports alockout mechanism that includes a lockout member that is linearlymovable between a locked position and an unlocked position. The driveassembly is movable from a retracted position to an advanced position tomove the actuation sled and knife assembly from its retracted positionto its advanced position. In the locked position, the lockout memberobstructs movement of the drive assembly from its retracted positiontowards its advanced position.

FIG. 1 illustrates a surgical stapling device according to aspects ofthe disclosure shown generally as stapling device 10. The staplingdevice 10 includes a handle assembly 12, an elongate body 14, and a toolassembly 16. The elongate body 14 defines a longitudinal axis “X” (FIG.1 ). The handle assembly 12 includes a body 18 that defines a hand grip18 a, a plurality of actuator buttons 20, and a rotation knob 22. Therotation knob 22 is rotatably supported on a distal portion of the body18 of the handle assembly 12 and supports the elongate body 14 tofacilitate rotation of the elongate body 14 and the tool assembly 16 inrelation to the handle assembly 12 about the longitudinal axis “X”. Theactuator buttons 20 control operation of the various functions of thestapling device 10 including articulation, clamping, firing, and cuttingof tissue.

The tool assembly 16 includes an anvil assembly 24 and a cartridgeassembly 26 that are that are coupled together to facilitate movement ofthe tool assembly 16 between open and clamped positions. Although thestapling device 10 is illustrated as an electrically powered staplingdevice, it is envisioned that the disclosed tool assembly 16 would alsobe suitable for use with manually powered surgical stapling devices androbotically operated stapling systems. U.S. Pat. No. 9,055,943 disclosesa surgical stapling device including a powered handle assembly, U.S.Pat. No. 6,241,139 discloses a surgical stapling device including amanually actuated handle assembly, and U.S. Pat. No. 9,962,159 disclosesa stapling device that is configured for use with a robotic system.

FIGS. 2-5 illustrate the cartridge assembly 26 (FIG. 1 ) which includesa staple cartridge 28 and a channel member 30 that defines a recess 30 athat receives the staple cartridge 28. In aspects of the disclosure, thestaple cartridge 28 is releasably supported within the recess 30 a ofthe channel member 30 and is replaceable to facilitate reuse of thestapling device 10.

The staple cartridge 28 includes a cartridge body 32, an actuation sledand knife assembly 34 (FIG. 4 ), pushers 36 (FIG. 5 ), staples 38 (FIG.5 ), and a base plate 40. The cartridge body 32 defines a central knifeslot 42 and staple receiving pockets 44. In aspects of the disclosure,the staple receiving pockets 44 are aligned in rows that are positionedon each side of the central knife slot 42. Although three rows of staplereceiving pockets 44 are shown on each side of the central knife slot42, it is envisioned that the cartridge body 32 may define one or morerows of staple receiving pockets 44 on each side of the central knifeslot 42. Each of the staple receiving pockets 44 receives one of thestaples 38 and one of the pushers 36. The pushers 36 support the staples38 and are engaged by an actuation sled 34 a of the actuation sled andknife assembly 34 as the actuation sled and knife assembly 34 isadvanced through the cartridge body 32 to eject the staples 38 from thecartridge body 32. The base plate 40 is secured to the bottom of thecartridge body 32 to prevent the pushers 36 and staples 38 from fallingfrom the cartridge body 32 prior to firing of the stapling device 10(FIG. 1 ).

FIGS. 4-5A illustrate the actuation sled and knife assembly 34 (FIG. 5A)which includes the actuation sled 34 a, a knife 66, and a biasing member68 (FIG. 5A). The actuation sled 34 a supports the knife 66 and ismovable within the cartridge body 32 (FIG. 5 ) from a retracted positionto an advanced position. The actuation sled 34 a includes a body 50(FIG. 5A) that has a central portion 52 and cam surfaces 54 that arepositioned on opposite sides of the central portion 52 of the body 50.The cam surfaces 54 define ramps that are positioned to engage thepushers 36 as the actuation sled 34 a moves from its retracted positiontowards its advanced position to sequentially eject the staples 38 fromthe cartridge body 32.

The central portion 52 of the actuation sled 34 a supports the knife 66and includes spaced walls 56 and a housing 58. Each of the spaced walls56 defines a circular recess 60 (FIG. 5A). The housing 58 extendsdistally of and is positioned between longitudinal axes defined by thespaced walls 56. The housing 58 defines a recess 62 that is aligned withthe central knife slot 42 of the cartridge body 32.

The knife 66 has a body 70 that has a Z-shaped configuration andincludes an elongate arm 72, a first portion 74 that extends downwardlyfrom a distal end of the elongate arm 72, and a second portion 76 thatextends upwardly from a proximal end of the elongate arm 72. The firstportion 74 of the body 70 of the knife 66 supports a pivot member 78that is received within the circular recesses 60 in the spaced walls 56of the actuation sled 34 a such that the knife 66 is pivotably supportedon the actuation sled 34 a between raised and lowered positions. In theraised position of the knife 66, the first portion 74 of the body 70 ofthe knife 66 is received within the recess 62 of the housing 58 of thecentral portion 52 of the actuation sled 34 a. The second portion 76 ofthe body 70 of the knife 66 defines a distally facing cutting edge 80that is shielded within the central knife slot 42 of the cartridge body32 when the knife 66 is in the lowered position and extends above thecentral knife slot 42 when the knife 66 is in the raised position. Thebody 70 of the knife 66 also includes a protrusion 82 that extendslaterally of the elongate arm 72. In aspects of the disclosure, theprotrusion 82 is positioned on the proximal portion of the elongate arm72 of the knife 66.

The biasing member 68 of the actuation sled and knife assembly 34 isreceived within the recess 62 of the housing 58 of the central portion52 of the actuation sled 34 a and engages the first portion 74 of thebody 70 of the knife 66 at a position above an axis defined by the pivotmember 78 of the knife 66 to urge the knife 66 towards the loweredposition. In aspects of the disclosure, the biasing member 68 includes acoil spring although it is envisioned that other types of biasingmechanisms or members could be used in place of the coil spring.

FIGS. 6 and 7 illustrate the anvil assembly 24 which includes an anvilcover 90 and an anvil plate 92. The anvil cover 90 includes a mountingportion 94, and a cover portion 96 (FIG. 15 ) that extends distally fromthe mounting portion 94 along the anvil plate 92. The mounting portion94 includes spaced extensions 98 that define bores 100 and extenddownwardly from the anvil plate 92 towards the channel 30 of thecartridge assembly 26. The anvil plate 92 includes a tissue engagingsurface 102 that is in juxtaposed relation to the staple cartridge 28when the tool assembly 16 is in a clamped position (FIG. 1 ). The tissueengaging surface 102 defines a plurality of staple deforming recesses104. The distal edge of the spaced extensions 98 define tissue stops 98a that are positioned slightly distal of the proximal-most stapledeforming recesses 104. The anvil plate 92 has a side opposite to thetissue engaging surface 102 that defines an elongated recess 91(FIG. 16). The anvil cover 90 is secured to the anvil plate 92, e.g., by weldingor crimping, such that the cover portion 96 (FIG. 15 ) of the anvilcover 90 encloses the elongated recess 91 of the anvil plate 92 todefine a channel 93 (FIG. 16 ) within the anvil assembly 24. The anvilplate 92 also defines a central knife slot 108 that extends through thetissue engaging surface 102 of the anvil plate 92 and communicates withthe elongated recess (not shown) of the anvil plate 92.

The bores 100 in the extensions 98 of the anvil cover 90 receive pivotmembers 112 (FIG. 2 ) that extend through the bores 100 into bores (notshown) defined in a proximal portion of the channel member 30 (FIG. 2 )to pivotably secure the anvil assembly 24 to the cartridge assembly 26.In aspects of the disclosure, the cartridge assembly 26 can pivottowards the anvil assembly 24 between the open and clamped positions. Itis envisioned that the tool assembly 16 (FIG. 2 ) could also beconfigured to pivot toward the cartridge assembly 26.

The anvil assembly 24 includes a lockout mechanism 114 (FIG. 7 )illustrated in FIGS. 6-11 that is supported on the anvil plate 92between the extensions 98 of the mounting portion 94 of the anvilassembly 24 proximally of the tissue engaging surface 102 of the anvilplate 92. In aspects of the disclosure, the lockout mechanism 114 issupported on an outer surface 102 a of the anvil plate 92 that iscontiguous with the tissue engaging surface 102 of the anvil plate 92.The lockout mechanism 114 includes a lockout member 116 and a biasingmember 118. The lockout member 116 is received within a housing 120secured to the surface 102 a of the anvil plate 92 and defines a cavity122. In aspects of the disclosure, the housing 120 has a rectangularconfiguration and defines an opening 124 (FIG. 7 ) that faces thecentral knife slot 108.

The lockout member 116 includes a body 125 that has a first end portionthat is received within the cavity 122 of the housing 120 supported onthe anvil plate 92 of the anvil assembly 24 and a second end portionthat extends transversely through the opening 124 of the housing 120towards the central knife slot 108 of the anvil assembly 24. The firstend portion of the body 125 of the lockout member 116 supports wings 128that extend distally and proximally from the body 125. The wings 128extend from the body 125 within the cavity 122 defined by the housing120 to prevent the lockout member 116 from passing entirely through theopening 124. In a locked position of the lockout mechanism 114, thewings 128 engage an inner wall 120 a (FIG. 11 ) of the housing 120 thatdefines the opening 124. The second end portion of the body 125 of thelockout member 116 includes a distally facing cam surface 126 and aproximally facing stop surface 127. The distally facing cam surface 126defines a plane that forms an acute angle with a longitudinal axisdefined by the central knife slot 108 of the anvil plate 92. Theproximally facing stop surface 127 defines a plane that is substantiallyperpendicular to the longitudinal axis of the central knife slot 108 ofthe anvil plate 92.

The biasing member 118 of the lockout mechanism 114 is positioned withinthe cavity 122 of the housing 120 to urge the lockout member 116 from anunlocked position spaced outwardly of the central knife slot 108 of theanvil assembly 24 towards a locked position. In the locked position, thelockout member 116 extends at least partially across the central knifeslot 108 of the anvil assembly 24 to obstruct advancement of the driveassembly 130. In aspects of the disclosure, the biasing member 118 issecured to a post 129 supported on the anvil assembly 24 within thecavity 122 of the housing 120 such that the biasing member 118 ispositioned in compression between the post 129 and the lockout member116. In some aspects of the disclosure, the lockout member 116 defines abore 129 a (FIG. 8 ) that receives one end of the biasing member 118. Inaspects of the disclosure, the biasing member 118 includes a coil springalthough the use of other types of biasing members is envisioned.

FIGS. 12 and 13 illustrate a drive assembly 130 of the stapling device10 (FIG. 1 ) which includes a resilient and/or flexible drive beam 132and a working member 134. The resilient drive beam 132 has a proximalportion (not shown) that is coupled to a drive rod (not shown) supportedwithin the elongate body 14 of the stapling device 10 (FIG. 1 ) and adistal portion that is coupled to the working member 134. In aspects ofthe disclosure, the resilient drive beam 132 is formed from laminatedsheets of material, e.g., steel, that are welded to the working member134. Alternately other materials of construction and securementtechniques are envisioned.

The working member 134 of the drive assembly 130 has an I-beamconfiguration and includes a first beam 138, a second beam 140, and avertical strut 142 that connects the first beam 138 to the second beam140. The vertical strut 142 defines a cutout 142 a (FIG. 13 ) that ispositioned beneath the first beam 138 and receives the second portion 76(FIG. 4 ) of the knife 66 when the knife 66 is moved to its raisedposition. The working member 134 is positioned proximally of theactuation sled 34 a (FIG. 12 ) and is movable through the tool assembly16 between retracted and advanced positions to move the actuation sledand knife assembly 34 through the tool assembly 16 (FIG. 1 ) from itsretracted position to its advanced position. As the working member 134moves through the cartridge assembly 26, the first beam 138 is receivedwithin the channel 93 (FIG. 16 ) defined within the anvil assembly 24(FIG. 6 ), the second beam 140 is engaged with the cartridge assembly26, and the vertical strut 142 moves through the central knife slots 42(FIG. 3 ) and 108 (FIG. 6 ) of the cartridge body 32 and the anvil plate92, respectively.

The vertical strut 142 defines a cam channel 152. The cam channel 152(FIG. 13 ) is angled upwardly and proximally from a central portion ofthe vertical strut 142 and is positioned to receive the protrusion 82 ofthe knife 66 (FIG. 4 ) when the drive assembly 130 is moved from itsretracted position towards its advanced position to move the knife 66from its lowered position to its raised position.

FIG. 14 illustrates the drive assembly 130 in its retracted position.When the drive assembly 130 is in its retracted position, the toolassembly 16 is in the open position with the cartridge assembly 26pivoted away from the anvil assembly 24, and the working member 134 ofthe drive assembly 130 is aligned with the anvil assembly 24. Theactuation sled and drive assembly 34 is supported in the cartridgeassembly 26 and is misaligned with the drive assembly 130. In theretracted position of the drive assembly 130, the lockout member 116 ofthe lockout mechanism 114 extends at least partially across the centralknife slot 108 (FIG. 6 ) of the anvil assembly 24 and is positionedwithin the cutout 142 a of the vertical strut 142.

FIGS. 15 and 16 illustrate the proximal portion of the tool assembly 16as the drive assembly 130 is advanced from its retracted positiontowards a clamped position in the direction of arrow “A”. As the workingmember 134 of the drive assembly 130 is advanced towards its clampedposition, the working member 134 moves into engagement with the toolassembly 16 to move the tool assembly 16 from the open position (FIG. 1) to the clamped position. In the clamped position of the drive assembly130, the vertical strut 142 of the working member 134 of the driveassembly 130 is still spaced from the central portion of the actuationsled 34 a of the actuation sled and knife assembly 34 such that theactuation sled and knife assembly 34 remains in its retracted position.The lockout member 116 of the lockout mechanism 114 also remains in thelocked position and extends at least partially across the central knifeslot 108 (FIG. 6 ) of the anvil assembly 24 into the cutout 142 a of thevertical strut 142.

FIGS. 16 and 17, 16 illustrate a schematic view of the drive assembly130 and the actuation sled and knife assembly 34 as the drive assembly130 advances from the clamped position to move the knife 66 from thelowered position (FIG. 15 ) to the raised position (FIG. 17 ). When thedrive assembly 130 moves from its clamped position towards its advancedposition, the protrusion 82 (FIG. 4 ) on the knife 66 is received in thecam channel 152 (FIG. 13 ) in the vertical strut 142 of the driveassembly 130. As the drive assembly 130 continues to advance, theprotrusion 82 of the knife 66 moves upwardly through the cam channel 152to pivot the knife 66 about the pivot member 78 (FIG. 4 ) in thedirection of arrow “B” in FIG. 17 from the lowered position to theraised position. When the knife 66 is in the raised position, thevertical strut 142 of the working member 134 of the drive assembly 130is positioned in abutting relation to the central portion 52 of theactuation sled 34 a such that further advancement of the drive assembly130 advances the actuation sled and knife assembly 34 through thecartridge body 32 (FIG. 5 ) of the staple cartridge 28.

FIG. 18 illustrates the interaction between the knife 66 and the lockoutmechanism 114 as the knife 66 moves from the lowered position to theraised position. When the knife 66 is moved in the direction of arrow“C” in FIG. 18 from the lowered position to the raised position, thesecond portion 76 (FIG. 17 ) of the body 70 of the knife 66 engages thedistally facing cam surface 126 of the lockout member 116 to urge thelockout member 116 in the direction of arrow “D” against the urging ofthe biasing member 118 from the locked position extending at leastpartially across the central knife slot 108 of the anvil assembly 24further into the housing 120 of the lockout mechanism 114 to theunlocked position. When the lockout member 116 of the lockout mechanism114 is moved to the unlocked position upon movement of the knife 66 tothe raised position, the drive assembly 130 is free to move from itsclamped position to its advanced position to advance the actuation sledand knife assembly 34 through the cartridge body 32 (FIG. 5 ) to ejectthe staples 38 from the staple cartridge 28 (FIG. 5 ) and to cut tissueclamped between the anvil assembly 24 and the cartridge assembly 26. Itis noted that the lockout member 116 is retained in the unlockedposition as the drive assembly 130 moves through the cartridge body 32of the staple cartridge 28 via engagement with the flexible drive beam132 of the drive assembly 130.

FIGS. 19 and 20 illustrate the drive assembly and the anvil assembly 24as the drive assembly 130 is moved from its advanced position back toits retracted position. When the drive assembly 130 moves from itsadvanced position back to its retracted position in the direction ofarrows “E” in FIG. 19 , the actuation sled and knife assembly 34 remainsin its advanced position and the flexible drive beam 132 engages thelockout member 116 of the lockout mechanism 114 to retain the lockoutmember 116 in the unlocked position. When the working member 134 movesproximally past the lockout member 116 of the lockout mechanism 114, thelockout member 116 is moved by the biasing member 118 back to the lockedposition. In the locked position, the lockout member 116 moves back intothe cutout 142 a of the vertical strut 142 of the working member 134 ofthe drive assembly 130 such that the proximally facing stop surface 127is positioned at least partially across the central knife slot 108 ofthe anvil assembly 24 to prevent readvancement of the drive assembly130.

In some aspects of the disclosure, depending on the configuration of thedrive assembly, the distally facing cam surface 126 of the lockoutmember 116 may be positioned to engage the vertical strut 142 of thedrive assembly 130 as the drive assembly is moved from the advancedposition to its retracted position to move the lockout member 116 fromthe locked position to the unlocked position.

When the staple cartridge 28 does not include an actuation sled andknife assembly 34 or a knife 66, the lockout member 116 cannot be movedfrom the locked position (FIG. 20 ) to the unlocked position asdescribed above. As such, the stapling device 10 (FIG. 1 ) cannot befired. The disclosed lockout mechanism 114 prevents refiring of thestapling 10 (FIG. 1 ) with a spent staple cartridge 28 (FIG. 5 ) andalso prevents firing of a stapling device 10 that includes a staplecartridge that does not have a knife present.

Persons skilled in the art will understand that the devices and methodsspecifically described herein and illustrated in the accompanyingdrawings are non-limiting exemplary embodiments. It is envisioned thatthe elements and features illustrated or described in connection withone exemplary embodiment may be combined with the elements and featuresof another without departing from the scope of the disclosure. As well,one skilled in the art will appreciate further features and advantagesof the disclosure based on the above-described embodiments. Accordingly,the disclosure is not to be limited by what has been particularly shownand described, except as indicated by the appended claims.

1. (canceled)
 2. A surgical stapling device comprising: an elongate bodyhaving a proximal portion and a distal portion; a tool assemblysupported on the distal portion of the elongate body, the tool assemblyincluding a cartridge assembly and an anvil assembly that are coupledtogether to facilitate movement of the tool assembly between open andclamped positions, the anvil assembly including a lockout mechanism thatis linearly movable from a locked position to an unlocked position; anda drive assembly movable in relation to the tool assembly between aretracted position and an advanced position to move the tool assemblybetween the open and clamped positions, wherein the lockout mechanism ispositioned to prevent movement of the drive assembly from its retractedposition to its advanced position when the lockout mechanism is in thelocked position.
 3. The surgical stapling device of claim 2, wherein thelockout mechanism includes a lockout member that is movable between thelocked position and the unlocked position.
 4. The surgical staplingdevice of claim 3, wherein the lockout mechanism includes a biasingmember that is positioned to urge the lockout member towards the lockedposition.
 5. The surgical stapling device of claim 4, wherein the anvilassembly includes an anvil plate that supports a housing that defines anopening, the lockout member and the biasing member positioned within thehousing.
 6. The surgical stapling device of claim 5, wherein the lockoutmember is movable through the opening in the housing between the lockedposition and the unlocked position.
 7. The surgical stapling device ofclaim 3, wherein the anvil assembly includes an anvil plate that definesa knife slot having a longitudinal axis, and the lockout member extendsacross at least a portion of the central knife slot when the lockoutmember is in the locked position.
 8. The surgical stapling device ofclaim 7, wherein the drive assembly includes a working member having anI-beam configuration, the working member having a first beam, a secondbeam, and a vertical strut that connects the first beam to the secondbeam, the vertical strut positioned to translate through the centralknife slot of the anvil plate as the drive assembly moves between itsretracted and advanced positions.
 9. The surgical stapling device ofclaim 8, wherein the lockout member has a distally facing cam surfacethat defines a plane, the plane defining an acute angle with thelongitudinal axis of the central knife slot of the anvil plate, thedistally facing cam surface engaging the vertical strut of the driveassembly as the drive assembly is moved from the advanced position toits retracted position to move the lockout member from the lockedposition to the unlocked position.
 10. The surgical stapling device ofclaim 3, wherein the lockout member includes a proximally facing stopsurface that defines a plane that is substantially perpendicular to thelongitudinal axis of the central knife slot of the anvil plate.
 11. Thesurgical stapling device of claim 10, wherein the lockout member ispositioned to engage a knife of an actuation sled and knife assembly ofa cartridge assembly to move the lockout member to the unlockedposition.
 12. An anvil assembly comprising: an anvil plate defining aknife slot having a longitudinal axis; and a lockout mechanism, thelockout member being linearly movable from a locked position to anunlocked position, the actuation sled and knife assembly beingpositioned to urge the lockout mechanism to its unlocked position whenthe actuation sled and knife assembly is in its retracted position. 13.The anvil assembly of claim 12, wherein the lockout mechanism includes alockout member that is movable between the locked and unlockedpositions.
 14. The anvil assembly of claim 13, wherein the lockoutmechanism includes a biasing member that is positioned to urge thelockout member to the locked position.
 15. The anvil assembly of claim14, wherein the anvil assembly includes an anvil plate that supports ahousing that defines an opening, the lockout member and the biasingmember positioned within the housing.
 16. The anvil assembly of claim15, wherein the lockout member is movable through the opening in thehousing between the locked and unlocked positions.
 17. The anvilassembly of claim 13, wherein the anvil assembly includes an anvil platethat defines a central knife slot that defines a longitudinal axis, andthe lockout member extends across at least a portion of the centralknife slot when the lockout member is in the locked position.
 18. Theanvil assembly of claim 17, wherein the lockout member has a distallyfacing cam surface that defines a plane, the plane defining an acuteangle with the longitudinal axis of the central knife slot of the anvilplate.
 19. The anvil assembly of claim 18, wherein the lockout memberincludes a proximally facing stop surface that defines a plane that issubstantially perpendicular to the longitudinal axis of the centralknife slot of the anvil plate.
 20. The anvil assembly of claim 19,wherein the lockout member is positioned to engage a knife of anactuation sled and knife assembly of a cartridge assembly to move thelockout member to the unlocked position.
 21. A tool assembly comprising:a cartridge assembly including a staple cartridge; an anvil assemblydefining a longitudinal axis coupled to the cartridge assembly tofacilitate movement of the tool assembly between an open position and aclamped position; and a lockout mechanism supported on the anvilassembly at a longitudinally fixed position, the lockout member linearlymovable along an axis transverse to the longitudinal axis from a lockedposition to an unlocked position.